Adjustable-pitch drums are well known in the art. See, for example, U.S. Pat. Nos. 4,048,895 and 4,121,493 (among others) issued to R. L. May. As discussed in these patents, a pitch-changing mechanism is mounted on the drum shell, and controlled by the musician to change the pitch of the drum by rotating the drum (the drum affixed to a threaded rod positioned vertical within the drum shell). Rotation of the drum functions to increase or decrease the tension of the drum head and the pitch of the drum (depending on the direction of rotation).
In most musical ensembles, a variety of different percussion instruments are used. There are instances where it would be convenient to include a snare drum for a particular event or musical performance, but the cost, size and various other component requirements makes it prohibitive to provide multiple numbers of drums for each event.
The ability to add a snare effect to another drum has a variety of uses, and is particularly advantageous in that the number of different drums that are needed to provide different sounds is reduced. For example, in trap sets, stage events, recording sessions, marching band events, and the like, the ability to reduce the number of different physical elements (in this case, drums), is always beneficial (particularly from an economic point of view, as well as efficiency of packing and unpacking instruments).
While the advent of the adjustable-pitch timpani drum has allowed for some additional features to be added to different musical performances, there is still a requirement in most cases to provide various sizes and types of snare drums, floor toms, mounted toms, roto-toms, etc.